/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.extensions.gcp.storage;



import com.bff.gaia.unified.sdk.extensions.gcp.options.GcsOptions;

import com.bff.gaia.unified.sdk.extensions.gcp.util.gcsfs.GcsPath;

import com.bff.gaia.unified.sdk.io.fs.ResourceId;

import com.bff.gaia.unified.sdk.options.PipelineOptions;



import java.io.IOException;



import static com.bff.gaia.unified.vendor.guava.com.google.common.base.Preconditions.checkArgument;



/** GCP implementation of {@link PathValidator}. Only GCS paths are allowed. */

public class GcsPathValidator implements PathValidator {



  private GcsOptions gcpOptions;



  private GcsPathValidator(GcsOptions options) {

    this.gcpOptions = options;

  }



  public static GcsPathValidator fromOptions(PipelineOptions options) {

    return new GcsPathValidator(options.as(GcsOptions.class));

  }



  /** Validates the the input GCS path is accessible and that the path is well formed. */

  @Override

  public void validateInputFilePatternSupported(String filepattern) {

    getGcsPath(filepattern);

    verifyPath(filepattern);

    verifyPathIsAccessible(filepattern, "Could not find file %s");

  }



  /** Validates the the output GCS path is accessible and that the path is well formed. */

  @Override

  public void validateOutputFilePrefixSupported(String filePrefix) {

    verifyPath(filePrefix);

    verifyPathIsAccessible(filePrefix, "Output path does not exist or is not writeable: %s");

  }



  @Override

  public void validateOutputResourceSupported(ResourceId resourceId) {

    checkArgument(

        "gs".equals(resourceId.getScheme()),

        "Expected a valid 'gs://' path but was given: '%s'",

        resourceId);

    verifyPath(resourceId.toString());

  }



  @Override

  public String verifyPath(String path) {

    GcsPath gcsPath = getGcsPath(path);

    checkArgument(gcsPath.isAbsolute(), "Must provide absolute paths for Dataflow");

    checkArgument(

        !gcsPath.getObject().isEmpty(),

        "Missing object or bucket in path: '%s', did you mean: 'gs://some-bucket/%s'?",

        gcsPath,

        gcsPath.getBucket());

    checkArgument(

        !gcsPath.getObject().contains("//"),

        "Dataflow Service does not allow objects with consecutive slashes");

    return gcsPath.toResourceName();

  }



  private void verifyPathIsAccessible(String path, String errorMessage) {

    GcsPath gcsPath = getGcsPath(path);

    try {

      checkArgument(gcpOptions.getGcsUtil().bucketAccessible(gcsPath), errorMessage, path);

    } catch (IOException e) {

      throw new RuntimeException(

          String.format("Unable to verify that GCS bucket gs://%s exists.", gcsPath.getBucket()),

          e);

    }

  }



  private GcsPath getGcsPath(String path) {

    try {

      return GcsPath.fromUri(path);

    } catch (IllegalArgumentException e) {

      throw new IllegalArgumentException(

          String.format("Expected a valid 'gs://' path but was given '%s'", path), e);

    }

  }

}